This invention relates to a method for making a material used as a substitute for vitreous enamel. The invention also relates to making emblems from this material.
Decorative plaques and emblems are widely used throughout a number of industries. In the past a colored vitreous frit was flowed into a bronze substrate and fired at 1250.degree. F. The glass-like vitreous enamel served to beautify the product and protect the decorative emblem from weathering should the plaque or emblem be exposed to the environment. Today plastics are primarily used for producing such plaques and emblems.
For example, in Loew (U.S. Pat. No. 3,654,062) there is disclosed a process of injection molding a decorative Mylar facing sheet over a vinyl plastic body. The plaque is coated with a layer of protective varnish on the outer surface of the facing sheet. Other molding processes, such as compression molding (either one or two shot), are also well known in the art. See for instance, U.S. Pat. Nos. 2,244,565; 2,931,119; 3,075,249; and 3,114,597.
Likewise, polyurethane molding compositions are also well known in the art. Thus, U.S. Pat. Nos. 3,337,476; 3,391,101; and 3,393,243 disclose polyurethane compositions. Pat. No. 3,391,101, then, states that the compounds disclosed therein may be "poured into the mold as a liquid" (Col. 1, lines 49-50); although, this is actually in the context of dealing a pipe rather than producing a molded product. None of these patents disclose casting a polyurethane upon a substrate to produce a decorative emblem.